Fuse switch disconnector Schneider Electric STI 3‑pole for 10x38 mm cylindrical fuses, model A9N15656

The Schneider Electric STI fuse switch disconnector is a 3‑pole unit designed to accept 10×38 mm cylindrical cartridge fuses. It provides a compact, panel-mounted solution for isolating and switching fused circuits in industrial and commercial electrical installations. The device integrates a fused disconnect function that facilitates safe maintenance and reliable overcurrent protection where cartridge fuses are used.

Advantages

This 3‑pole fuse switch disconnector offers a standardized mounting footprint for electrical panels and enclosures, enabling quick replacement of cartridge fuses. Its mechanical switching mechanism ensures positive isolation of the circuit when opened, and the design supports clear visual identification of fuse condition. Built to fit common 10×38 mm cylindrical fuses, it simplifies inventory management and maintenance routines.

Suitable for (tasks / use cases)

• Isolation of three‑phase circuits during maintenance or service operations
• Overcurrent protection in industrial machinery and control panels using 10×38 mm cartridge fuses
• Retrofit or new installations in commercial distribution boards and switchgear
• Applications requiring a clear fused disconnection point for safety procedures

When it may not be suitable

This fuse switch disconnector is specifically designed for use with 10×38 mm cylindrical cartridge fuses and three‑pole circuits. It is not appropriate where different fuse sizes or non‑cartridge protective devices (such as miniature circuit breakers or NH fuses) are required. Applications requiring integrated electronic trip characteristics, remote operation or monitoring cannot be fulfilled by a simple mechanical fuse switch disconnector without additional components.

Key specifications

• Poles: 3‑pole configuration for three‑phase circuits
• Compatible fuse form factor: 10×38 mm cylindrical cartridge fuses
• Mounting type: panel or distribution board mounting (standardized dimensions)
• Functional role: fused disconnect switch for isolation and overcurrent protection

How to use

Install the fuse switch disconnector in the panel cutout or holder prepared for the standardized mounting footprint, securing it according to panel instructions and local electrical codes. Fit the appropriate 10×38 mm cylindrical fuses into the cartridge holders, ensuring correct fuse ratings are selected for the circuit. Use the external handle or actuator to switch the device to the open position before performing maintenance; verify absence of voltage with suitable testing equipment. Replace blown fuses only after identifying and correcting the fault condition, and restore the switch to the closed position to re‑energize the circuit.

What to consider before purchase

• Confirm compatibility with 10×38 mm cylindrical cartridge fuses used in your installation
• Verify the required current and breaking capacity of fuses to match circuit protection needs
• Ensure panel space and mounting dimensions correspond to the device footprint
• Check whether additional features (remote indication, interlocks, or monitoring) are needed separately

Usage recommendations

For safe operation, always select cartridge fuses with appropriate current ratings and breaking capacity for the protected circuit, follow local wiring regulations during installation, and use a calibrated voltage tester to confirm isolation before any service work.